This application relates generally to gas turbine engines and, more particularly, to combustors for gas turbine engine.
Within known jet engines, air leaves a compressor with a relatively high axial velocity. To facilitate reducing pressure losses while increasing combustion efficiency, the air velocity is reduced as it enters a combustor. More specifically, the combustor includes an inlet section, known as a diffuser, that decelerates the airflow.
To facilitate reducing an effect of diffusion of the airflow on engine specific fuel consumption (SFC), a diffusion process within the combustor should provide a relatively high static pressure recovery of the airflow downstream from the diffuser while simultaneously reducing flow losses. Diffusion is determined by a ratio of an outlet area of the diffuser to an inlet area of the diffuser, a ratio known as an effective area ratio of the diffuser. To achieve a given pressure recovery with relatively low-pressure losses, at least some known diffusers have relatively long lengths measured between the inlet and outlet areas of the diffuser. As the length of the diffuser is increased, a weight of the engine is increased. However, within known diffusers, as the length of the diffuser is reduced, static pressure recovery is reduced.
To facilitate improving the diffusion process, at least some known diffusers include two diffuser channels separated by a circumferentially extending splitter. Because each channel is smaller than an original single channel, to achieve a desired effective area ratio, the two channels have increased heights. Although airflow exiting a single channel is often more uniform than that of airflow exiting two channel diffusers, often the flow from single channels does not spread out enough within the combustor, and the performance of the combustor is adversely affected.
In an exemplary embodiment, a combustor for a gas turbine engine facilitates reducing combustor dump pressure losses to improve combustor and engine performance. The combustor includes a diffuser that diffuses airflow directed into the combustor. The diffuser includes an outer wall, an inner wall, and a plurality of splitter vanes between the outer wall and the inner wall. The splitter vanes are spaced radially apart, and each splitter vane is spaced radially from a respective diffuser wall to define at least three diffuser passages within the diffuser. More specifically, an outer passage, an inner passage, and a central passage are defined by the splitter vanes. The diffuser facilitates a gas turbine engine including a high area ratio and reduced engine length and weight, without sacrificing engine pressure losses or specific fuel consumption, SFC.
In use, the diffuser splitter vanes divide the airflow into the three separate passages which act in parallel. More specifically, the outer passage diffuses and channels the axial airflow radially outward to facilitate reducing dump losses while improving pressure recovery within the combustor, the central passage diffuses the axial airflow and maintains the airflow in an axial direction to facilitate minimizing flow losses, and the inner passage diffuses the airflow and channels the axial airflow radially inward to facilitate reducing dump losses while improving pressure recovery within the combustor. As a result, the diffuser facilitates reducing combustor dump losses to improve combustor performance without sacrificing engine specific fuel consumption, SFC.